Blast magneto



Aug. 7, 1928. 1,680,261

A. u. DAVIS BLAST MAGNETO Filed Nov. 8, 192

Patented Aug. 7, 1928.

1,680,261 UNITEDSTATES PATEjNTbFFICE. i

ALFRED i1. DAVIS; ctr-BALTIMORE, MARYLAND, ASSIGNQRTO DAVIS INSTRUMENT MANUFACTURING COMPANY; INCORPORATED, aconroaacrrouor MARYLAND.

BLAST MAGNETQ. l 1

if Application filed November 8, 1926. j SerialNo. 147,097.

This invention relates to improvements in blast magnetos, and has for its object to provide a simple and eflicient device for generating a current of electricity to be carried to any desired point for the purpose of firing a blast.

The invention consists of the novel construction and arrangement of the parts and combination of parts hereinafter more fully set forth in the following specification and pointed out in detail in the appended claim.

In the accompanying drawings,-

Figure 1 is a side elevation of my invention. j y

Figure 2 is a similar View to Figure 1 the casing being in the vertical section.

Figure 3 is a detail elevation of the parts removable from the casing showing the opposite side from that shown in Figure 2.

Figure 4 is a section on the line 22 of Figure 3.

Figure 5 ture. I

Figure 6 is a detail view of the armature showing the contact plates in section.

Referring to the accompanying drawings, forming part of this specification, and in is a detail side view of the armawhich like reference numerals designate like parts throughout the several views thereof, 1 designates the outer casing having a removable cover 2 and binding posts 3 and 4. Between the binding posts 3 and 4 and the cover 2 is an insulating piece 5. The bind ing post 3 is insulated from the cover 2 by means of the insulating piece 5 and the, insulating disk 6. The binding post 4 is grounded to the cover 2. Within the casing l is a laminated magnet 7 composed of a number of plates, held together by the sleeve 8 and the retaining plate 9 which latter held in position by the pin 10. Mountedin the sleeve 8 is a segment gear 11 having a recess in its face across which the key pin 12 projects. The shaft of the segment gear 11 which projects in to the sleeve 8 is provided with a coiled spring 13 to hold the said segment gear in its normal position.

The said segment gearjll is in mesh with the pinion '14 rigidly, fixed to the shaft 15. The said shaft 15 is mounted in the bearing 16 and is provided on its opposite end with a gear wheel 17 which latter is in mesh with the pinion 18 on the shaft 19 of the armature. The said armature is composed ofthe' core 20 secured to the plates 21 and 22 and wound with the wire 23. The plate 21 carries a pawl 24 pivoted at one end thereto and having its free end co-operating 'with the ratchet 25 just back of and carried with the pinion 18. The plates 21 and 22 are provided with the shafts 19 and 26 respectively which are mounted in the bearing plates 27 and 28 and revolve therein. One

' end of the wire 23 is grounded on the core 29 and the other end is secured to .a metal disk 29 which is insulated from the plate The contact plate 31 is in constant contact with the metal disk 29 and is insulated from the bearing plate 28 by the insulation washer 32. The

said contact plate 31 has a wire 33 connected thereto at one end and its opposite end secured to the pin 34 having a nut 35 to hold the Wire in position on said pin. Said pin projects through the magnet plates 7 and is insulated therefrom. To the opposite end of the pin 34 is secured the contact plate 36 which is also insulated from the magnet plates and has its upper end in constant contact with the binding post 3. Projecting through the upper end of the magnet 7 is a stop 37 to limit the movement of the segment gear 11.

WVhen the device is to be operated the wires leading to the charge to be fired are connected to the binding posts 3 and 4. The key is then inserted in the casing 1 across the pin 12. A quick turn of the key will revolve the segment gear 11, cause the shaft 15 to revolve, which in turn through the 22 by the washer 30. The said metal disk '29 is provided with an aperture through which the shaft 26 projects.

mechanism described causes the armature to be rapidly revolved and thereby generate current which is then carried off through the disk 29 and contact plate 31 through the wire 33 and Contact plate 36 to the binding post 3 and through the wires connected to posts 3 and 4 to the charge to and insulated therefrom and having one 8 end of the armature wire connected thereto, a contact plate in constant contact with said disk and connected with one of said binding pinion, and having a recess in one side posts, a pinion on one end of the armature thereof, a pin projecting across said recess 10 shaft, a gear in mesh with said pinion, a of said segment gear and means co-operatshaft on which said gear is mounted, a pining with said pin for turning the segment ion on opposite end of said last mentioned gear and revolving the said armature.

shaft, a sleeve to which the magnet plates In testimony whereof I aflix my signature.

are secured, a segment gear mounted in said sleeve and in mesh with the last mentioned 7 ALFRED U. DAVIS. 

